SMS Names Disappear?

There are one or two people in my contacts list that show up in SMS messages as "Unnamed". Seems like it used to work correctly before the first hot-sync. Tried hard reset, deleting contact in question on palm and computer and re-adding, and also deleting the sms database in the backup before re-syncing. No good. If you choose new message, and look up in contacts, I can select that person, and their name comes up, but after I send the message and look in the "sent messages" folder their name has been changed back to "Unnamed". Any suggestions? Treo 650, Sprint, btw.

I have exactly the same problem with my 650. No names for SMS chat threads, no Caller ID. very frustrating. Have you found a solution, or do you think the 650 ROM update might sort it out (which is available to you at the moment, since you're a Sprint user)? Would like to know what you find out.
Thanks